Microstructure-property relation and evolution in friction stir welding of naturally aged 6063 aluminium alloy

The development of the microstructure and mechanical properties during friction stir welding of 6063-T4 aluminium alloy was investigated through electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM) techniques and mechanical testing. Grain boundary and dislocation strengthening were observed to be the dominant strengthening mechanisms occurring in the stir zone (SZ). While the precipitates morphologies were sensitive to the weld zone temperatures, the grain size and grain boundary misorientations were related to strain